Birder's Journal: Looking At a Handy New Guide

Robert Winkler for National Geographic News

October 23, 2002

When it was published two years ago, The Sibley Guide to Birds,written and illustrated by David Allen Sibley, was an immediate success.

Anticipation was high because Sibley, a leader of birding tours and the son of a well-known ornithologist, had worked for 12 years on the guide and its 6,600 illustrations of 810 species of North American birds. He previously was the illustrator of Hawks in Flight and A Guide to Bird-Finding in New Jersey.

With so many illustrations, including flight poses and identifiable variations of species, The Sibley Guide is much larger than competitors such as The National Geographic Field Guide and Roger Tory Peterson's classic Field Guide to the Birds of Eastern and Central North America.

But size and a correspondingly hefty $35 cover price haven't hurt sales: about 700,000 copies of The Sibley Guide are in print. (In a nod to portability, Sibley Guide publisher Alfred A. Knopf will issue eastern and western versions of the book next spring.)

Although heavy on artworkthe highly variable red-tailed hawk, for example, required some 40 paintingsin other respects The Sibley Guide seems guided by the philosophy that less is more. Generally, it depicts only two species per page, with illustrations of each placed within a wide column, against a white background.

A brief description introduces each bird, and labeled pointers show the field marks of adults (in breeding and non-breeding plumages), juveniles, and distinguishable populations. Each column ends with a short paragraph on voice, and a range map.

The consistent depiction of the flying bird at the top of each column was an innovation for a North American guide, and Sibley peppered his roomy pages with nuances of identification that wouldn't have fit into a book of typical field guide dimensions.

Few people lug The Sibley Guide into the fieldit's a reference better left at home or in the car, used to resolve identifications that elude a true field guide.

Tips for the Field

Having a good bird guide is one thing; using it well is another.

Like high-quality binoculars, a good guide is a sharp tool, but it won't be very useful unless you bring something to the equation. David Sibley's latest book, Sibley's Birding Basics, concentrates on the human side of field identification.

In this slim paperback, Sibley expands on the introductory sections to The Sibley Guide, describing his birding techniques and supporting salient points with a variety of illustrations, including diagrams, sketches, and full-color portraits.

Birders at all levels of experience will find nuggets of value.

The section on field skills, for example, contains this advice: "Watch the edges of a flock and pay special attention to outlying birds or those that act differently; these may be different species."

Later in the same section, Sibley explains how flock movements indicate the presence of a hawk: "Many small birds react to an aerial predator by forming a tight flock and swerving back and forth around it, not allowing it to get above them or to single out one member of the flock."

On the challenges of birding, Sibley commiserates: "Identification is like a matching game with a time limit," he says. "On one side you have images in a book or in your head, and on the other side you have a bunch of flitting, skulking birds."

And on "pishing"trying to attract birds by imitating their alarm callshe mildly scolds: "Pishing can be overdone."

The chapter on the challenges of bird identification explains how to differentiate similar species, such as the downy and the hairy woodpecker. It also touches on identifying birds by their "jizz," birding parlance for the unique impression a species conveys, even when glimpsed for a fraction of a second.

Tricks of Appearance

For me, Sibley's notes on misidentification are the most interesting.

He explains how incorrect assumptions and a form of peer pressure led him and other experienced birders initially to misidentify New Jersey's first record of a calliope hummingbird. A similar "group hysteria," he adds, gripped hundreds of birders in California, who for days mistakenly took a skylark for a Smith's longspur.

If at times you've puzzled over birds you know well, Sibley will help you see why that's only natural.

A high-contrast background makes a bird appear larger. So does fog. In dim light, however, a bird appears smaller.

Lighting conditions, reflective surfaces, and backgrounds influence the intensity of a bird's colors. As they adjust to changes in temperature and wind speed, birds alter their posture, and by flexing muscles at the feather bases, they puff or flatten their plumage.

Such adjustments can seem to affect not only a bird's size, but also its proportions and color patterns.

Sibley covers flight behavior, vocalizations, and feathers, devoting more pages to featherstheir structure, growth, and arrangement, and how they shape and pattern a birdthan to any other topic. The chapter on molt is difficult but reasonably short, so I read it twice for a better grasp of the somewhat esoteric Humphrey-Parkes system of molts, which Sibley deems essential to an understanding of age and plumage variation.

The cover of Sibley's Birding Basics describes it as a book that will tell you how to identify birds. That's fair enough, but as Sibley writes in the first chapter, "The methods and clues I put forth will be meaningful only after you have had some personal experience with them. The book covers some of the larger concepts; refining the ideas and filling in the details is up to the individual."

In other words, read the book and let the advice percolate. Then grab your binoculars and get out in the field.

Robert Winkler's book of essays on his adventures with birds of the "suburban wilderness" will be published in 2003 by National Geographic Books.